Provide support for subjectAltName on PHP < 5.6

main
Chris Smith 9 years ago
parent 837fa805ec
commit 7e2a015e9b

@ -33,6 +33,7 @@ class RemoteFilesystem
private $progress;
private $lastProgress;
private $options = array();
private $peerCertificateMap = array();
private $disableTls = false;
private $retryAuthFailure;
private $lastHeaders;
@ -252,6 +253,18 @@ class RemoteFilesystem
});
try {
$result = file_get_contents($fileUrl, false, $ctx);
if (PHP_VERSION_ID < 50600 && !empty($options['ssl']['peer_fingerprint'])) {
// Emulate fingerprint validation on PHP < 5.6
$params = stream_context_get_params($ctx);
$expectedPeerFingerprint = $options['ssl']['peer_fingerprint'];
$peerFingerprint = $this->getCertificateFingerprint($params['options']['ssl']['peer_certificate']);
// Constant time compare??!
if ($expectedPeerFingerprint !== $peerFingerprint) {
throw new TransportException('Peer fingerprint did not match');
}
}
} catch (\Exception $e) {
if ($e instanceof TransportException && !empty($http_response_header[0])) {
$e->setHeaders($http_response_header);
@ -353,6 +366,32 @@ class RemoteFilesystem
}
}
if (false === $result && false !== strpos($errorMessage, 'Peer certificate') && PHP_VERSION_ID < 50600) {
// Certificate name error, PHP doesn't support subjectAltName on PHP < 5.6
// The procedure to handle sAN for older PHP's is:
//
// 1. Open socket to remote server and fetch certificate (disabling peer
// validation because PHP errors without giving up the certificate.)
//
// 2. Verifying the domain in the URL against the names in the sAN field.
// If there is a match record the authority [host/port], certificate
// common name, and certificate fingerprint.
//
// 3. Retry the original request but changing the CN_match parameter to
// the common name extracted from the certificate in step 2.
//
// 4. To prevent any attempt at being hoodwinked by switching the
// certificate between steps 2 and 3 the fingerprint of the certificate
// presented in step 3 is compared against the one recorded in step 2.
$certDetails = $this->getCertificateCnAndFp($this->fileUrl, $options);
if ($certDetails) {
$this->peerCertificateMap[$this->getUrlAuthority($this->fileUrl)] = $certDetails;
$this->retry = true;
}
}
if ($this->retry) {
$this->retry = false;
@ -529,6 +568,14 @@ class RemoteFilesystem
$tlsOptions['ssl']['SNI_server_name'] = $host;
}
if (isset($this->peerCertificateMap[$this->getUrlAuthority($originUrl)])) {
// Handle subjectAltName on lesser PHP's.
$certMap = $this->peerCertificateMap[$this->getUrlAuthority($originUrl)];
$tlsOptions['ssl']['CN_match'] = $certMap['cn'];
$tlsOptions['ssl']['peer_fingerprint'] = $certMap['fp'];
}
$headers = array();
if (extension_loaded('zlib')) {
@ -625,6 +672,7 @@ class RemoteFilesystem
'verify_peer' => true,
'verify_depth' => 7,
'SNI_enabled' => true,
'capture_peer_cert' => true,
)
);
@ -800,4 +848,113 @@ class RemoteFilesystem
unset($source, $target);
}
private function getCertificateCnAndFp($url, $options)
{
$context = StreamContextFactory::getContext($url, $options, array('options' => array(
'ssl' => array(
'capture_peer_cert' => true,
'verify_peer' => false, // Yes this is fucking insane! But PHP is lame.
))
));
if (false === $handle = @fopen($url, 'rb', false, $context)) {
return;
}
// Close non authenticated connection without reading any content.
fclose($handle);
$params = stream_context_get_params($context);
if (!empty($params['options']['ssl']['peer_certificate'])) {
$peerCertificate = $params['options']['ssl']['peer_certificate'];
$fp = $this->getCertificateFingerprint($peerCertificate);
$cert = openssl_x509_parse($peerCertificate, false);
$commonName = $cert['subject']['commonName'];
$subjectAltName = preg_split('{\s*,\s*}', $cert['extensions']['subjectAltName']);
$subjectAltName = array_filter(array_map(function ($name) {
if (0 === strpos($name, 'DNS:')) {
return substr($name, 4);
}
}, $subjectAltName));
if (in_array(parse_url($url, PHP_URL_HOST), $subjectAltName, true)) {
return array(
'cn' => $commonName,
'fp' => $fp,
);
}
// TODO: Support wildcards.
}
}
/**
* Get the certificate pin.
*
* By Kevin McArthur of StormTide Digital Studios Inc.
* @KevinSMcArthur / https://github.com/StormTide
*
* See http://tools.ietf.org/html/draft-ietf-websec-key-pinning-02
*
* This method was adapted from Sslurp.
* https://github.com/EvanDotPro/Sslurp
*
* (c) Evan Coury <me@evancoury.com>
*
* For the full copyright and license information, please see below:
*
* Copyright (c) 2013, Evan Coury
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
private function getCertificateFingerprint($certificate)
{
$pubkeydetails = openssl_pkey_get_details(openssl_get_publickey($certificate));
$pubkeypem = $pubkeydetails['key'];
//Convert PEM to DER before SHA1'ing
$start = '-----BEGIN PUBLIC KEY-----';
$end = '-----END PUBLIC KEY-----';
$pemtrim = substr($pubkeypem, (strpos($pubkeypem, $start) + strlen($start)), (strlen($pubkeypem) - strpos($pubkeypem, $end)) * (-1));
$der = base64_decode($pemtrim);
return sha1($der);
}
private function getUrlAuthority($url)
{
$defaultPorts = array(
'ftp' => 21,
'http' => 80,
'https' => 443,
);
$defaultPort = $defaultPorts[parse_url($this->fileUrl, PHP_URL_SCHEME)];
$port = parse_url($this->fileUrl, PHP_URL_PORT) ?: $defaultPort;
return parse_url($this->fileUrl, PHP_URL_HOST).':'.$port;
}
}

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